Table of Contents
What is the application of varistors?
Varistors are used as control or compensation elements in circuits either to provide optimal operating conditions or to protect against excessive transient voltages. When used as protection devices, they shunt the current created by the excessive voltage away from sensitive components when triggered.
Where can I use varistor?
Varistors are used to protect a circuit from high voltage surges. When a high voltage surge is applied to a circuit, the outcome is usually catastrophic to the circuit. A capacitor may be installed across the signal lines. However, this capacitor cannot suppress voltage surges.
What is MOV and its uses?
An MOV is a voltage dependent device which has an electrical behavior similar to back to back zener diodes. ▪ When exposed to high voltage transients, the MOV’s resistance. changes from a near open circuit to a very low value, thus clamping the transient voltage to a safe level.
Why MOV is used in power supply?
Application of MOV: MOV is often used in parallel with the protection device to clamp the voltage when the circuit is subjected to overvoltage, absorbing excessive current to protect the subsequent circuit.
What are the applications of voltage-dependent resistor?
These VDRs are useful for a wide variety of applications that can include: Telephone and other communication line protection. Radio communication equipment transient suppression. Surge protector power strips.
What are the applications of voltage dependent resistor?
Where is MOV used?
A Metal Oxide Varistor (MOV) is a protection component used in power supply circuits that is powered directly from AC mains. It is used to protect the circuit from high voltage spikes by varying its resistance.
Why is MOV used?
MOV’s are the most used component to protect heavy devices from transient voltages. A diode junction is formed between each border of the grain and its immediate neighbour. Thus an MOV is basically a huge number of diodes that are connected parallel to each other.
Which of the following circuits is protected by metal oxide varistor?
Varistors, also called metal-oxide varistors (MOVs), are used to protect sensitive circuits from a variety of overvoltage conditions. Essentially, these voltage-dependent, nonlinear devices have electrical characteristics similar to back-to- back Zener diodes.
Why we use MOV in circuit?
An MOV is a voltage dependent device which has an electrical behavior similar to back to back zener diodes. changes from a near open circuit to a very low value, thus clamping the transient voltage to a safe level. pulse is absorbed by the Varistor, thereby protecting vulnerable circuit components.
How do I select a varistor?
Select a model to provide the required voltage-clamping characteristic A final consideration is to choose the appropriate package style to suit the application. Consider the maximum continuous voltage that will be applied to the varistor including any high line conditions (i.e., 110% or more of nominal voltage).
How to choose the right metal oxide varistor (MOV)?
The first step of choosing a MOV is determining the continuous working voltage that will be provided across the varistor,you have to choose the varistor with maximum AC or
What does clamping voltage of a metal oxide varistor mean?
Clamping voltage is the maximum voltage allowed to pass through the circuitry to the connected equipment when tested with the UL test surge. 330 volts is the lowest rating allowed by the UL and the rating must be stated on the unit. The lower the number, the better. Other allowed ratings are 400, 600, 800, and 1000. Some manufacturers use a rating called “let through voltage” to
What is varistor diode?
Varistors are voltage dependent, nonlinear devices which have an electrical behavior similar to back-to-back zener diodes. The symmetrical, sharp breakdown characteristics shown in Figure 1 enable the varistor to provide excellent transient suppression performance.
Does metal oxide also produce oxygen?
pressure of oxygen will be in equilibrium with the metal and metal oxide at a given temperature. The significance of this is that, if the oxygen partial pressure is higher than the equilibrium value, the metal will be oxidized, and if it is lower than the equilibrium value then the oxide will be reduced.